1. Field of the Invention
The subject invention generally pertains to a refrigeration compressor, and more specifically to the shape of the compressor's housing.
2. Description of Related Art
Refrigeration systems often include a compressor that is installed in a hermetically sealed housing. In many applications, it is important to minimize the noise generated by the compressor. Consequently, various housing designs have been developed to help attenuate the noise. One approach has been to provide a housing with an irregular shape to minimize resonance brought on by sound waves repeatedly reflecting between two facing surfaces of the housing.
For example, the housing of U.S. Pat. No. 4,729,723 arranges some opposite wall sections in a nonparallel relationship. These sections, however, do not appear to extend a significant distance around the circumference of the shell before being interrupted by parallel facing surfaces. In particular, it appears in FIG. 2 of the '723 patent, that section 5 directly faces section 6, and an upper portion of FIG. 2 faces a lower portion. It also appears, in FIG. 4, that the left side of upper shell 3 directly faces the right side. The '723 patent is just one example demonstrating the difficulty of achieving radial asymmetry that extends uninterrupted all the way around a compressor, without having the housing appear as though it were custom formed manually.
Another example is the housing of U.S. Pat. No. 5,281,105. FIG. 3 of the '105 patent not only shows a great deal of radial symmetry, but it also appears that point 43 directly faces point 44, and point 37 directly faces point 38.
The housing shown in FIG. 2 of U.S. Pat. No. 5,487,648 appears to have surface 16 directly facing surface 17. Also, the surface at the 10:30 position appears to directly face the surface at the 4:30 position. Any radially asymmetrical portions do not appear to extend much more than 45 degrees around the circumference of the housing before being interrupted by opposite parallel segments.
U.S. Pat. No. 4,345,882 is yet another example of a housing that attempts to address the noise issue, but the housing appears very symmetrical in FIG. 8, (which is a top view of FIG. 6). For a given horizontal plane, it also appears that points 14a, b, and c directly face 16a, b, and c respectively.
No horizontal cross-section is clearly shown for the compressor housing of U.S. Pat. No. 5,391,054; however, based on FIG. 6, it appears that any asymmetry lying along a horizontal plane extends less than halfway around upper shell 10.